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Discuss Tap tails and isolation valve roblem. in the Plumbing Forum | Plumbing Advice area at PlumbersForums.net

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Hi all.

I'm after some help... I hope I can be clear enough...

After being in 9 years our bathroom basin tap started dripping. It's a single mixer tap, one with a lever that you move left or right for hot or cold water. I realised it wasn't like the ones we had in the old days where you took the top off and changed a washer so I asked for a quote and got one back for £400 which shocked me a bit (I gave up work to be a full time carer and I've had no income for 10 years, I live off my savings so £400 is major to me) so I thought I'd do it myself, how hard can it be? Two flexible tap tails connected to isolation valves in the cupboard under the sink so it looked easy, and it was.

I bought a new tap from B&Q with all I'd need in the box and fitting it was a doddle. I took the old tap and its flexible tails off and threw them away and fitted the new one and everything went well but I was disappointed to find that the arm of the tap only just cleared the rim of the basin and I couldn't get my hands under the stream. I went back to B&Q to see if they had a tap that'd go further over the basin but when I measured them I found they were all about the same size, so no real improvement.

I got a slightly bigger tap off Amazon and again it came with everything in the box but when I went to fit it I found the nuts were too small to fit the isolation valves. I thought I'd use the tails off the tap I got from B&Q but they're a different size where they fit to the tap. Since then I've been back to B&Q (who couldn't help or maybe just didn't understand) trawled the various suppliers on the internet and not been able to find what I want, either a bigger tap with tails that'll fit my isolation valves or some tails that'll fit my existing tap and isolation valves.

I've tried to measure the isolation valve and it seems to be about 20/22mm. A plumbers supplier on the local industrial estate said it would be 3/4". The tap tails from B&Q seems to be 6mm at the tap end and 3/4" (?) at the isolation valve and the Amazon tap seems to have tap tails that are 8mm at the tap end and 15mm (?) at the isolation valve end. The bloke at the plumbers supplier said my best bet is to replace the isolation valves with 15mm ones. He seemed surprised about the isolation valves I had and said they "Shouldn't be that size." He did have a lovely tap that was big enough but it had copper pipe tails (12mm at the tap end, I think he said) which I assume will need to be soldered?

What's the more usual set up for an isolation valve and have we really got something we shouldn't have? The tap from B&Q came with exactly what I needed so surely our set up can't be all that unusual?

What I think I need is some flexible tap tails that'll fit my tap (8mm at the tap end) and my isolation valves, 3/4"? or maybe an adapter that can take my isolation valve from 3/4 to 15mm.

Is any of this possible or am I going to have to get someone in to either replace the isolation valves so that I can use the tap I bought off Amazon or buy a new tap with copper tails that need to be soldered in?

I thought this was going to be such an easy job... take the old one out and fit the new one... but at the moment I haven't been able to find a way forward and we still have a tap which we can only get our finger tips under.

Any advice would be wonderful!
 
1. A fair number of taps come with flexible connectors. The ends which screw into the tap usually has a male thread of M10 or M12 with an "O" ring after the threaded part. The other ends tend to have a 1/2" or 3/8" BSP female thread. The 1/2" BSP version will screw directly onto the isolation valve, although this is not good practice, its better to have a piece of pipe or an adaptor (e.g. Screwfix 2665R) between valve and flexi. If its a 3/8" (obviously smaller than 1/2") then use Screwfix 6089R to connect.

BSP stands for British Standard Pipe. The sizes (1/2, 3/4 etc) refer to the INSIDE diameter of the pipe they are designed for. Thus the threads themselves also have to allow for the thickness of the pipe wall (times 2), which is why a 1/2" BSP male thread is just under 20 mm across the threads.
 
Thanks for that but I'm not sure I understand.

The male end that screws into the tap is either 6 or 8mm, I have two. Those two have different female ends that screw onto the male thread of the isolation valve, one looking like a 15mm thread and the other looking like 22mm to me. It's hard to be exact but that's what they look like just measuring them by eye with a ruler. It's the 22mm tap tail that fits the isolation valve whilst the 15mm is way too small.

That 2665r looks like it'll fit the 15mm tap tail I have but it looks to be an unthreaded pipe at the other end, is it just a push fit? And will it fit the isolation valve that looks like it has a 22mm male thread?

And a PS.
After reading the comments I now understand that these are a push fit, but there are comments about them not being long enough and being loose and leaking so I'm not sure but at the cost they'll be worth a try before I give up and send the tap back.

I'm still worried about the size so if anyone knows... are these push fit adapter likely to fit into the isolation valves I have with the 22mm thread? I'm also worried about getting a good tight seal on the tap tails as these adapters don't seem to have any gripable surface to hold and tighten onto the tails with. Are these really a good idea?
 
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Thanks again.

This bit phases me...

"For use with swivel nut connections on flexible tap tails. Ensures washer fits flat, securing seal. Fits into a standard 15mm isolating valve."

I'm not completely sure that's what we have as the tap tails I have have a 15mm thread and they're way too small to fit onto the 22mm thread on the isolation valve.

Are you saying these adapters designed to fit a 15mm isolation valve will fit inside the (22mm threaded) isolation valve we have and give a good seal?

Sorry to be dense...
 
For once I'm going to suggest a photo of the isolation valve with a tape measure or a coin placed nearby to gauge sizes
 
Thank you for replying, good idea about pictures...

This is the B&Q tap which fits great but the tap arm is too short and we can't get our hands under the stream. The thread on the tap tail and isolation valve look like 22mm...

P1030698.jpg


P1030699.jpg


This is the tap tail off the tap from Amazon, the thread looks like 15mm and it's too small to connect to the existing isolation valve...

P1030701.jpg


As I mentioned above, I can't use the 22mm B&Q tap tails on the Amazon tap as the male ends at the tap end are different sizes.

I hope this makes things clear, thanks again for any help in finding tap tails or any sort of adapter which will allow me to fit... something. If not we'll have to put up with only getting our fingertips under the water stream.
 
1. The isolation valve you show is a 15 mm isolation valve. It has 1/2" BSP threads and compression nuts at each end, NOT 15 mm nuts.
2. The Amazon tap has what looks like 3/8" BSP nuts at the non-tap end. If this is correct, then to fit it you will need:
2a. The Screwfix 3/8 adaptors already mentioned in post #2 or the Toolstation equivalents quoted by JCPlumber in post #5
2b. A nut and olive to fit each isolation valve. I'd suggest you just buy another 15 mm compression isolation valve and use the nut and olive off each end on the existing isolation valves.
2c. fit the nut and olive onto the adaptor. Insert the unthreaded end of the adaptor into the isolation valve and do up the nut. Do the nuts up with a spanner. Tighten just enough to stop the adaptor being able to turn, then another 1/2 turn on the spanner.
2d. Screw the 3/8" end of the flexi onto the threaded end of the adaptor. Tighten up firmly by hand, then a bit extra with a spanner. There should be a rubber washer inside the flexi end, and this makes the seal. It only needs to be nipped up tight enough not to leak.
3. The B&Q tap clearly has 1/2" BSP female threaded ends. To fit these, do as 2. above, but use the other (1/2" BSP)
quoted adaptor.
4. NONE of these fittings are push fit.
 
Nice explanation there Steadyon, I might just add to use a 6 or 8" long adjustable spanner to hold the isolation valve firm when tightening the new nut and olive of which I would a copper olive not brass olive.
 
£400.00 pound not sounding so rich now.

Appreciate the personal circumstances but this a real good indication of just what a professional brings to the table.
Not just materials and time, but knowledge.

And as you are learning, the knowledge is priceless.
 
Thanks steadyon.

I've just googled the BSP thread sizes and now I see why I've been confused on the measurements.
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Yes, I've used a spanner on the isolation valve every time.

Simon.
I appreciate that plumbers have knowledge and deserve their money. I served my time as an electrician before moving into computers where I worked very long stressful days for very long stressful years so I do know about hard work and long hours and being paid what you're worth.

I stopped working 10 years ago to look after someone with a few issues including alzheimers and I've not undertaken paid work or taken a penny off the state since and had precious few days relief in those 10 years so sorry but I make no apologies for trying to save a few £ here. If the guy had quoted £200 and explained why I'd have paid the money and sucked it up but as it is I'll thank you all again and see if I can get this done on a budget that leaves me some money for the next little maintenance job. It is that tight.

Thank you all and goodnight from a grateful me.
 
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1. .....screw directly onto the isolation valve, although this is not good practice, its better to have a piece of pipe or an adaptor (e.g. Screwfix 2665R) between valve and flexi.

Genuinely looking to learn/explore.

Whats the reasoning behind this?

Why is it not - good/best practice to screw directly into an iso valve?
 
Because the isolating valve has an end designed to accept an olive, as such it tapers to a very thin edge. The washer in the flexi therefore has a very small area to seal onto, not only that but over tightening can easily cut into the washer.
The adapters mentioned above have a wider area to seal to and this is machined flat so will not cut the washer.
In practice there must be millions straight onto the isolating valve and often no problem occurs, but the above is considered best practice.
(The adapter is relatively new to our market and can be substituted with a male iron, which is what was used previously)
 

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